Insulated plasterboard

I used this. http://www.kingspaninsulation.co.uk...erm-K118-Insulated-Plasterboard/Overview.aspx

Other manufacturers will have equivalents you could compare against too.

 

I've also been toying with the same idea after I spotted some insulated plasterboards at Wickes last week.
Does dot & dab leave a slight gap at the back?
Does this air gap matter?
Is it preferable to have a gap or try and eliminate all air by pushing together with a mechanical fixing?
I've seen some mechanical fixings on YouTube videos so any advice on this would be useful too? Which ones to use?

 

I insulated a wall in my last place but battened it out. 50mm insulation, vapour barrier and ordinary plasterboard on top. Made a big difference to heat in room.

 

Battening took up 50mm plus plasterboard and plaster. Not a massive amount

 

Celotex boards can be dot and dabbed. Just did this in my garage conversion no probs, solid as a rock and easy to do as they are already rigid with the insulation on the back

 

Yeah celotex - https://www.travisperkins.co.uk/Cel...rmal-Laminate-1200mm-x-2400mm-x-60mm/p/629245

 

I'm looking to do a similar thing (though batten or dot and dab are fine with me). My concern is condensation. The boards will be attached internally to the external walls, which are solid brick and the external walls have a concrete/sand render, so are not breathable.

My fear that is that hot air will hit the cold surface of the brick wall and condense with no means of escape. I'm not really keen to ventilate the void between the wall and insulation due to the speed of heat loss when this is done. Obviously a vapour control layer is required but where exactly this layer goes I'm not sure as there is contradicting information on VCLs on the internet.

 

No idea Ross- but the idea is that the insulted board is impervious to moisture so none should get through it to land on the wall.

Best thing I'd suggest is to contact a maker of such boards like Knauf or Celotex and ask them.

 

Hi Tore.

Just D&D it.

If space is a premium, then bear in mind that even the thinnest insulated board will transform your room's insulation. I used 35mm total thickness board due to space issues and it's superb.

If you were to double the thickness from 25 (insulation layer) to 50, you would get nothing approaching a doubling of insulation value. There would only be a marginal improvement.

Why? Because the 'first' 25mm will have done most of the work, so the extra thickness has less actual heat transfer to deal with

I don't have true figures, but say the 25mm layer improves the insulation by a factor of 50, then only one fiftieth of the heat loss is now passing through that wall. What benefit will a further 25mm layer do?! Yep - a fiftieth of a fiftieth - piddly all.

I'm not saying be a cheapskate, but only to not worry if space is at a premium and you wanna go thinnest. Certainly go thicker if you can afford to.

Ok, fitting. Get at least a couple of sturdy and dead-straight timbers like 4x2 CLS. The main issue with D&Ding insulated sheets is that they are prone to having a slight bow or warp in them, and can be more springy that plain p'board.

If you are a true DIYer like me, then I think I'd want to be well prepared with a few straight timber guides (the CLS as above) but possibly also a couple of timbers that'll brace the wall from the other side of the room if the boards you have have a warp in them and you have any suspicion they'll need holding in place whilst the adhesive sets (possible over-kill, but it's chust to guarantee the boards stay exactly flat whilst the adhesive sets - almost certainly not needed.)

Ok, take vertical levels of the wall so's you know if the boards need to compensate. Are you going on to a smooth plain plaster surface or down to bare brick? Bare brick/block will almost certainly be more uneven, so larger dabs needed.

Prepare everything - boards at the ready, trimmed down if necessary, straight edges, level, (and possible props from the other wall cut to length (ie to brace from the opposite wall (or a piece of furniture or summat solid) to against the levelling timbers you'll be using.)

Do a dry run - position the boards and see if they are sitting nicely.

If yes, remove, apply lots of dabs (if you are going on to a smooth level plaster wall, then each dab can be smaller than you'd use on a bare brick/block wall, but I would then add lots more of them...)

Board up, straight edges hard against them, and use the timbers to gently 'bang' the boards flat and close against the wall, whilst ensuring the timbers are always sitting flat against the boards - no board warps. Alternatively, place the timbers flat against the boards and then gently tap them in turn with a rubber mallet. Check at the board edges how tight you are going - if against smooth plaster, I'd be going less than a 10mm gap.) also hold the timbers horizontally on the boards to check against any bends or ripples that way (thicker insul board certainly shouldn't have this issue at all).

If the boards stay totally in place (which they should) then job jobbed. Move on to the next.

Use the timbers to span across from one board to another to ensure they are level with each other.

Report back - so we all know how to do it in future...

 

Oh, any window reveals you plan to go around? That needs thinking through - where the boards overlap (you'll see what I mean...)

You need to ensure that only the p'board layer of one board goes over the combined insulation and p'boar layer on the adjacent one. So that means neatly trimming away a strip of insulation from the back of one board - you'll soon see...

 

I'm planning on using this for a leg of my outside wall- kv600 4mm wallrock insulating wallpaper https://www.amazon.co.uk/Wallrock-KV600-Thermal-Liner/dp/B007FXRYIG

It sounds naff I know, but the reviews are mostly great... And I had a wall battened out in a previous rental and it was still cold, just not damp anymore. N the windows looked like portals n a bit weird cos of the added depth, albeit about 2"

Can anyone vouch for this stuff?

 

Wallrock KV600 is the bigger brother of the KV300 & Thermal Liner insulation, expensive, but it's impressive thermal wallpaper, only thing I found akward was the 1mtr width of the roll,but you soon get use to it, definitley made a difference to a cold north wall in a bedroom.
Hunt around you might find it cheaper.

http://www.erfurtmav.com/

Astramax probably has more experience of using Wallrock.